The decomposition of chemiluminescent chemical compounds to release electromagnetic energy, and especially optically detectable energy--usually luminescence in the form of visible light--is well known and understood. The incorporation of such light emitting reactants in art-recognized immunoassays, chemical assays, nucleic acid probe assays and chemical/physical probe techniques as the means by which the analyte, a substance whose presence, amount or structure is being determined, is actually identified or quantified has assumed increasing importance in recent years, particularly with the advent of enzymatically-cleavable 1,2-dioxetanes; see, for example, the abovementioned copending Bronstein, Bronstein et al and Edwards applications.